U.S. patent number 10,535,609 [Application Number 16/020,030] was granted by the patent office on 2020-01-14 for package structure and method for forming the same.
This patent grant is currently assigned to Taiwan Semiconductor Manufacturing Co., Ltd.. The grantee listed for this patent is TAIWAN SEMICONDUCTOR MANUFACTURING CO., LTD.. Invention is credited to Ming-Da Cheng, Ching-Hua Hsieh, Cheng-Ping Lin, Chih-Wei Lin, Wei-Hung Lin, Chung-Shi Liu, Yi-Da Tsai.
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United States Patent |
10,535,609 |
Tsai , et al. |
January 14, 2020 |
Package structure and method for forming the same
Abstract
Package structures and methods for forming the same are
provided. A package structure includes a package layer. The package
structure also includes an integrated circuit die and a first
connector embedded in the package layer. The package structure
further includes a redistribution layer over the package layer. The
integrated circuit die is electrically connected to the
redistribution layer through the first connector. In addition, the
package structure includes a passivation layer over the
redistribution layer. The package structure also includes a second
connector over the passivation layer. A first portion of the
redistribution layer and a second portion of the second connector
extend into the passivation layer. The second portion of the second
connector has a tapered profile along a direction from the
integrated circuit die towards the first connector.
Inventors: |
Tsai; Yi-Da (Dongshi Township,
Chiayi County, TW), Lin; Cheng-Ping (Hsinchu County,
TW), Lin; Wei-Hung (Xinfeng Township, Hsinchu County,
TW), Lin; Chih-Wei (Zhubei, TW), Cheng;
Ming-Da (Zhubei, TW), Hsieh; Ching-Hua (Hsinchu,
TW), Liu; Chung-Shi (Hsinchu, TW) |
Applicant: |
Name |
City |
State |
Country |
Type |
TAIWAN SEMICONDUCTOR MANUFACTURING CO., LTD. |
Hsinchu |
N/A |
TW |
|
|
Assignee: |
Taiwan Semiconductor Manufacturing
Co., Ltd. (Hsinchu, TW)
|
Family
ID: |
62064415 |
Appl.
No.: |
16/020,030 |
Filed: |
June 27, 2018 |
Prior Publication Data
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Document
Identifier |
Publication Date |
|
US 20180308800 A1 |
Oct 25, 2018 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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15347912 |
Nov 10, 2016 |
10014260 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L
24/96 (20130101); H01L 21/4853 (20130101); H01L
21/4857 (20130101); H01L 21/6835 (20130101); H01L
23/5386 (20130101); H01L 23/3135 (20130101); H01L
23/5389 (20130101); H01L 24/17 (20130101); H01L
23/295 (20130101); H01L 24/97 (20130101); H01L
21/561 (20130101); H01L 24/81 (20130101); H01L
21/565 (20130101); H01L 21/568 (20130101); H01L
21/56 (20130101); H01L 2924/18161 (20130101); H01L
2224/13144 (20130101); H01L 2224/81815 (20130101); H01L
2924/1304 (20130101); H01L 24/16 (20130101); H01L
2224/13101 (20130101); H01L 2224/13155 (20130101); H01L
2224/1146 (20130101); H01L 2224/11462 (20130101); H01L
2924/3511 (20130101); H01L 2924/181 (20130101); H01L
2224/81193 (20130101); H01L 2924/1203 (20130101); H01L
2224/13164 (20130101); H01L 2221/68381 (20130101); H01L
23/3128 (20130101); H01L 24/13 (20130101); H01L
2224/13147 (20130101); H01L 2224/81005 (20130101); H01L
24/32 (20130101); H01L 25/50 (20130101); H01L
2924/1434 (20130101); H01L 25/0655 (20130101); H01L
2221/68345 (20130101); H01L 2924/15311 (20130101); H01L
24/73 (20130101); H01L 2224/16227 (20130101); H01L
2924/14 (20130101); H01L 2224/73204 (20130101); H01L
2924/3511 (20130101); H01L 2924/00 (20130101); H01L
2924/1304 (20130101); H01L 2924/00012 (20130101); H01L
2924/1203 (20130101); H01L 2924/00012 (20130101); H01L
2224/13101 (20130101); H01L 2924/014 (20130101); H01L
2924/00014 (20130101); H01L 2924/181 (20130101); H01L
2924/00012 (20130101); H01L 2224/73204 (20130101); H01L
2224/32225 (20130101); H01L 2224/16225 (20130101); H01L
2924/00012 (20130101); H01L 2924/15311 (20130101); H01L
2224/73204 (20130101); H01L 2224/16225 (20130101); H01L
2224/32225 (20130101); H01L 2924/00012 (20130101); H01L
2224/81815 (20130101); H01L 2924/00014 (20130101); H01L
2924/14 (20130101); H01L 2924/00012 (20130101); H01L
2924/1434 (20130101); H01L 2924/00012 (20130101) |
Current International
Class: |
H01L
23/538 (20060101); H01L 23/00 (20060101); H01L
21/683 (20060101); H01L 23/31 (20060101); H01L
23/29 (20060101); H01L 21/56 (20060101); H01L
21/48 (20060101); H01L 25/00 (20060101); H01L
25/065 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Ahmad; Khaja
Attorney, Agent or Firm: Birch, Stewart, Kolasch &
Birch, LLP
Parent Case Text
CROSS REFERENCE
This Application is a divisional application of U.S. application
Ser. No. 15/347,912, filed on Nov. 10, 2016, the entirety of which
is incorporated by reference herein.
Claims
What is claimed is:
1. A package structure, comprising: a package layer; an integrated
circuit die and a first connector embedded in the package layer; a
redistribution layer over the package layer, wherein the integrated
circuit die is electrically connected to the redistribution layer
through the first connector; a passivation layer over the
redistribution layer; and a second connector over the passivation
layer, wherein a first portion of the redistribution layer and a
second portion of the second connector extend into the passivation
layer, and wherein the second portion of the second connector
covers an upper portion of a slope sidewall of the passivation
layer, and the first portion of the redistribution layer covers a
lower portion of the slope sidewall of the passivation layer,
wherein the slope sidewall of the passivation layer has a tapered
profile along a direction from the integrated circuit die towards
the first connector.
2. The package structure as claimed in claim 1, wherein the second
connector comprises an under bump metallurgy layer and a bump over
the under bump metallurgy layer, and wherein the passivation layer
has a top surface facing the second connector, and a bottom surface
of the bump is lower than the top surface of the passivation
layer.
3. The package structure as claimed in claim 1, further comprising:
a second package layer, wherein a sidewall of the integrated
circuit die adjoins the package layer and the second package layer,
and the package layer and the integrated circuit die are embedded
in the second package layer, and wherein the package layer
comprises first fillers having a first size, and the second package
layer comprises second fillers having a second size that is greater
than the first size.
4. The package structure as claimed in claim 3, further comprising:
a third package layer, wherein the second package layer has a
portion between the third package layer and the integrated circuit
die, wherein the third package layer comprises third fillers having
a third size that is greater than the second size.
5. The package structure as claimed in claim 1, further comprising:
a second package layer covering an edge of the passivation layer
and a first sidewall of the package layer, wherein the edge of the
passivation layer is between the first sidewall of the package
layer and a second sidewall of the second package layer from a top
view.
6. A package structure, comprising: a package layer; an integrated
circuit die embedded in the package layer, wherein the integrated
circuit die has an active surface and a non-active surface; a bump
embedded in the package layer, wherein the bump is coupled to the
active surface; a redistribution layer over the package layer,
wherein the integrated circuit die is electrically connected to the
redistribution layer through the bump; a passivation layer over the
redistribution layer; and a connector over the passivation layer,
wherein a first portion of the redistribution layer and a second
portion of the connector extend into the passivation layer and
contact with each other, and wherein the first portion of the
redistribution layer and the second portion of the connector
gradually shrink along a direction from the non-active surface
toward the active surface to form a slope sidewall.
7. The package structure as claimed in claim 6, wherein there is an
interface between the first and second portions in the passivation
layer, and wherein the passivation layer has a first surface, which
faces the integrated circuit die, and a second surface, which is
opposite to the first surface and is closer to the interface than
the first surface.
8. The package structure as claimed in claim 7, wherein the
redistribution layer comprises a conductive layer and a seed layer
between the conductive layer and the passivation layer, and wherein
the conductive layer and the seed layer extend along the first
surface into the passivation layer to electrically connect to the
connector.
9. The package structure as claimed in claim 8, wherein the
connector comprises a second bump and a second seed layer between
the second bump and the passivation layer, and wherein the second
seed layer extends along the second surface into the passivation
layer and adjoins the conductive layer and the seed layer.
10. The package structure as claimed in claim 9, wherein the second
bump is separated from the conductive layer and the seed layer by
the second seed layer.
11. The package structure as claimed in claim 6, further comprising
a second package layer, wherein the package layer has a portion
between the second package layer and the non-active surface.
12. The package structure as claimed in claim 11, wherein the
package layer comprises first fillers having a first size, and the
second package layer comprises second fillers having a second size
that is greater than the first size.
13. A package structure, comprising: a package layer; an integrated
circuit die and a bump embedded in the package layer; a
redistribution layer over the package layer, wherein the integrated
circuit die is electrically connected to the redistribution layer
through the bump; a passivation layer over the redistribution
layer, wherein a first portion of the redistribution layer extends
into the passivation layer, and the passivation layer comprises a
sidewall adjoining the first portion of the redistribution layer;
and a connector over the passivation layer, wherein a second
portion of the connector extends into the passivation layer to
electrically connect to the redistribution layer, and there is an
acute angle between the sidewall of the passivation layer and a
first surface of the passivation layer facing the connector,
wherein a lateral sidewall of the first portion of the
redistribution layer and a lateral sidewall of the second portion
of the connector are substantially coplanar in the passivation
layer and are inclined at the acute angle.
14. The package structure as claimed in claim 13, wherein the
passivation layer has a second surface opposite to the first
surface, the redistribution layer extends along the second surface
into the passivation layer, and the first portion of the
redistribution layer gradually shrinks along a direction from the
second surface to the first surface.
15. The package structure as claimed in claim 13, wherein the
passivation layer has a second surface opposite to the first
surface, the connector extends along the first surface into the
passivation layer, and the second portion of the connector
gradually shrinks along a direction from the second surface to the
first surface.
16. The package structure as claimed in claim 13, wherein the
redistribution layer comprises a conductive layer and a seed layer
between the conductive layer and the passivation layer, and wherein
the connector comprises a second bump and a second seed layer
between the second bump and the passivation layer, and a portion of
the second seed layer is sandwiched between the second bump and the
conductive layer.
17. The package structure as claimed in claim 16, wherein the
sidewall of the passivation layer is covered by the seed layer and
the second seed layer.
18. The package structure as claimed in claim 16, wherein the
conductive layer and the second bump is separated from the
passivation layer by the seed layer and the second seed layer.
19. The package structure as claimed in claim 1, wherein a lateral
sidewall of the first portion of the redistribution layer and a
lateral sidewall of the second portion of the second connector are
substantially coplanar in the passivation layer.
20. The package structure as claimed in claim 19, wherein the
second connector comprises an under bump metallurgy layer and a
bump over the under bump metallurgy layer, and a portion of the
under bump metallurgy layer forms the lateral sidewall of the
second portion of the second connector, and a portion of the bump
is located in a space defined by an inner wall of the portion of
the under bump metallurgy layer, and the space has a tapered
profile along the direction from the integrated circuit die towards
the first connector.
Description
BACKGROUND
With the constant evolution of semiconductor technology,
semiconductor dies are increasingly becoming smaller. More
functions, however, need to be integrated into these semiconductor
dies. Accordingly, these semiconductor dies have increasingly
greater numbers of I/O pads packaged into smaller areas, and the
density of the I/O pads is quickly rising. As a result, the
packaging of semiconductor dies is becoming more difficult.
Package technologies can be divided into multiple categories. In
one of the categories of packaging, dies are sawed from wafers
before they are packaged onto other wafers, and only
"known-good-dies" are packaged. An advantage of this packaging
technology is the possibility of forming fan-out chip packages,
which means that the I/O pads on a die can be redistributed to a
greater area than the die itself. Therefore, the number of I/O pads
packed on the surfaces of the dies can be increased.
New packaging technologies have been developed to further improve
the density and functions of semiconductor dies. These relatively
new types of packaging technologies for semiconductor dies face
manufacturing challenges, and they have not been entirely
satisfactory in all respects.
BRIEF DESCRIPTION OF THE DRAWINGS
Aspects of the present disclosure are best understood from the
following detailed description when read with the accompanying
figures. It should be noted that, in accordance with the standard
practice in the industry, various features are not drawn to scale.
In fact, the dimensions of the various features may be arbitrarily
increased or reduced for clarity of discussion.
FIGS. 1A-1I are cross-sectional views of various stages of a
process for forming a package structure, in accordance with some
embodiments.
FIG. 2 is a top view of one stage of a process for forming a
package structure, in accordance with some embodiments.
FIG. 3 is an enlarged cross-sectional view of a package structure,
in accordance with some embodiments.
FIG. 4 is a cross-sectional view of a package structure, in
accordance with some embodiments.
FIGS. 5A and 5B are cross-sectional views of various stages of a
process for forming a package structure, in accordance with some
embodiments.
DETAILED DESCRIPTION
The following disclosure provides many different embodiments, or
examples, for implementing different features of the provided
subject matter. Specific examples of components and arrangements
are described below to simplify the present disclosure. These are,
of course, merely examples and are not intended to be limiting. For
example, the formation of a first feature over or on a second
feature in the description that follows may include embodiments in
which the first and second features are formed in direct contact,
and may also include embodiments in which additional features may
be formed between the first and second features, such that the
first and second features may not be in direct contact. In
addition, the present disclosure may repeat reference numerals
and/or letters in the various examples. This repetition is for the
purpose of simplicity and clarity and does not in itself dictate a
relationship between the various embodiments and/or configurations
discussed.
Furthermore, spatially relative terms, such as "beneath," "below,"
"lower," "above," "upper" and the like, may be used herein for ease
of description to describe one element or feature's relationship to
another element(s) or feature(s) as illustrated in the figures. The
spatially relative terms are intended to encompass different
orientations of the device in use or operation in addition to the
orientation depicted in the figures. The apparatus may be otherwise
oriented (rotated 90 degrees or at other orientations) and the
spatially relative descriptors used herein may likewise be
interpreted accordingly.
Some embodiments of the disclosure are described. FIGS. 1A-1I are
cross-sectional views of various stages of a process for forming a
package structure, in accordance with some embodiments. FIG. 2 is a
top view of one stage of a process for forming a package structure,
in accordance with some embodiments. FIG. 3 is an enlarged
cross-sectional view of a package structure, in accordance with
some embodiments.
Additional operations can be provided before, during, and/or after
the stages described in FIGS. 1A-1I. Some of the stages that are
described can be replaced or eliminated for different embodiments.
Additional features can be added to the package structure. Some of
the features described below can be replaced or eliminated for
different embodiments. Although some embodiments are discussed with
operations performed in a particular order, these operations may be
performed in another logical order.
As shown in FIG. 1A, a carrier substrate 100 is provided, in
accordance with some embodiments. In some embodiments, the carrier
substrate 100 is used as a temporary substrate. The temporary
substrate provides mechanical and structural support during
subsequent processing steps, such as those described in more detail
later. Afterwards, the carrier substrate 300 may be removed.
In some embodiments, the carrier substrate 100 includes a
semiconductor substrate, a glass substrate, a ceramic substrate, a
polymer substrate, another suitable substrate, or a combination
thereof. In some embodiments, the carrier substrate 100 is a
silicon wafer or another suitable wafer.
Afterwards, an adhesive layer 110 is deposited over the carrier
substrate 100, in accordance with some embodiments. The adhesive
layer 110 may be made of glue, or may be a lamination material,
such as a foil. In some embodiments, the adhesive layer 110 is
photosensitive and is easily detached from the carrier substrate
100 by light irradiation. For example, shining ultra-violet (UV)
light or laser light on the carrier substrate 100 is used to detach
the adhesive layer 110. In some embodiments, the adhesive layer 110
is a light-to-heat-conversion (LTHC) coating. In some other
embodiments, the adhesive layer 110 is heat-sensitive and is easily
detached from the carrier substrate 100 when it is exposed to
heat.
Subsequently, a passivation layer 120 with openings 130 is formed
over the adhesive layer 110, in accordance with some embodiments.
As a result, the adhesive layer 110 is partially exposed from the
openings 130.
The passivation layer 120 has a surface 120A that faces the
adhesive layer 110, and a surface 120B that faces away from the
adhesive layer 110. The passivation layer 120 has a sidewall 120C
adjoining one of the openings 130. In some embodiments, the
sidewall 120C is inclined to the surfaces 120A and 120B. In some
embodiments, there is an acute angle between the sidewall 120C and
the surface 120A. In some embodiments, the angle .theta. between
the sidewall 120C and the surface 120A is greater than 0.degree.
and is less than or substantially equal to 90.degree.. However,
embodiments of the disclosure are not limited thereto. In some
other embodiments, the sidewall 120C is substantially perpendicular
to the surfaces 120A and 120B.
In some embodiments, the passivation layer 120 is made of a polymer
material. In some embodiments, the passivation layer 120 includes
polyimide, polybenzoxazole (PBO), benzocyclobutene (BCB), silicone,
acrylates, siloxane, another suitable material, or a combination
thereof. In some other embodiments, the passivation layer 120
includes non-organic materials. The non-organic materials may
include silicon oxide, un-doped silicate glass, silicon oxynitride,
solder resist (SR), silicon nitride, silicon carbide,
hexamethyldisilazane (HMDS), another suitable material, or a
combination thereof.
Multiple deposition, coating, and/or etching processes may be used
to form the passivation layer 120 with the openings 130. For
example, a chemical vapor deposition (CVD) process or a spin-on
coating process may be used to deposit the passivation layer 120.
Afterwards, an etching process may be used to form the openings
130.
As shown in FIG. 1B, a patterned redistribution layer including
conductive layers 140 and 150 is formed over the passivation layer
120, in accordance with some embodiments. The conductive layers 140
and 150 extend along the surface 120B of the passivation layer 120
and extend into the openings 130 of the passivation layer 120. The
conductive layer 140 is between the conductive layer 150 and the
surface 120B and extends between the conductive layer 150 and the
sidewall 120C.
In some embodiments, the openings 130 are substantially fully
filled with the conductive layers 140 and 150. In some other
embodiments, the openings 130 are substantially fully filled with
the conductive layers 140 and 150 and another material layer.
In some embodiments, the conductive layer 140 is a seed layer and
is thinner than the conductive layer 150. In some embodiments, the
conductive layer 140 includes titanium (Ti). However, embodiments
of the disclosure are not limited thereto. For example, the
conductive layer 140 may include Ti alloy, copper (Cu), Cu alloy,
another suitable seed material, or a combination thereof. The Ti
alloy or the Cu alloy may include silver, chromium, nickel, tin,
gold, tungsten, another suitable element, or a combination thereof.
In some embodiments, the conductive layer 140 is deposited using a
physical vapor deposition (PVD) process, a CVD process, another
applicable process, or a combination thereof.
In some embodiments, the conductive layer 150 is made of a metal
material. The metal material includes Cu, aluminum (Al), tungsten
(W), gold (Au), another suitable material, or a combination
thereof. In some embodiments, the conductive layer 150 is deposited
using an electroplating process, a sputtering process, another
applicable process, or a combination thereof. Multiple etching
processes may be used to pattern the conductive layers 140 and 150
to form the patterned redistribution layer.
As shown in FIG. 1C, a passivation layer 160 with openings is
formed over the passivation layer 120 and the conductive layer 150,
in accordance with some embodiments. The conductive layer 150 is
partially exposed from the openings of the passivation layer 160.
In some embodiments, the materials and/or formation methods of the
passivation layer 160 are similar to those of the passivation layer
120.
Afterwards, a patterned redistribution layer including conductive
layers 170 and 180 is formed over the passivation layer 160, in
accordance with some embodiments. The conductive layers 170 and 180
extend into the openings of the passivation layer 160. In some
embodiments, the materials and/or formation methods of the
conductive layers 170 and 180 are similar to those of the
conductive layers 140 and 150, respectively.
Subsequently, a passivation layer 190 with openings 200 is formed
over the passivation layer 160 and the conductive layer 180, in
accordance with some embodiments. As a result, the conductive layer
180 is partially exposed from the openings 200 to provide a landing
area for connectors, which will be described in more detail later.
The passivation layer 190 may or may not fill the openings of the
passivation layer 160. In some embodiments, the passivation layers
120, 160 and 190 and the carrier substrate 100 have a substantially
coplanar sidewall or edge 195. In some embodiments, the materials
and/or formation methods of the passivation layer 190 are similar
to those of the passivation layer 120.
As shown in FIG. 1D, multiple integrated circuit dies 210 are
bonded to the exposed portions of the conductive layer 180 through
connectors 220, in accordance with some embodiments. The integrated
circuit dies 210 are electrically connected to the redistribution
layers including the conductive layers 150, 160, 170 and 180
through the connectors 220. In some embodiments, the integrated
circuit dies 210 are arranged in an array inside edge 195, as shown
in FIG. 2.
In some embodiments, the integrated circuit dies 210 have an active
surface 210A that faces the passivation layer 190, and a non-active
surface 210B that faces away from the passivation layer 190. In
some embodiments, there is a space 230 between the active surface
210A of the integrated circuit dies 210 and the passivation layer
190.
The integrated circuit dies 210 are device dies including
transistors, diodes, or another suitable integrated circuit
element. The device dies may also include capacitors, inductors,
resistors, another integrated circuit element, or a combination
thereof. In some embodiments, the integrated circuit dies 210 are
sensor dies, logic dies, central processing unit (CPU) dies, memory
dies, or another suitable dies. For example, the integrated circuit
dies 210 may be High-Bandwidth Memory (HBM) elements, System on
Chip (SoC) elements, or a combination thereof.
In some embodiments, each of the connectors 220 includes a
conductive bump 222 and a solder layer 224. The conductive bump 222
is between one of the integrated circuit dies 210 and the solder
layer 224. The conductive bump 222 may be a conductive pillar,
another suitable conductive feature, or a combination thereof. In
some embodiments, the conductive bump 222 includes copper,
electroless nickel immersion gold (ENIG), electroless nickel
electroless palladium immersion gold (ENEPIG), another suitable
material, or a combination thereof.
In some embodiments, the solder layer 224 is over the passivation
layer 190 and fills the openings 200 to electrically connect to the
conductive layer 180. In some embodiments, a reflow process is
performed to bond the solder layer 224 and the conductive layer 180
together. However, embodiments of the disclosure are not limited
thereto. In some other embodiments, the solder layer 224 is
electrically connected to the conductive layer 180 through another
connector in the openings 200.
Many variations and/or modifications can be made to embodiments of
the disclosure. In some other embodiments, the connectors 220 do
not include conductive pillars. In some other embodiments, the
connectors 220 are solder bumps, solder balls, other suitable
connectors, or a combination thereof.
As shown in FIG. 1E, a package layer 240 is formed over the
passivation layer 190, in accordance with some embodiments. In some
embodiments, the package layer 240 extends over the non-active
surface 210B of the integrated circuit dies 210. As a result, the
integrated circuit dies 210 are embedded in the package layer 240.
In some embodiments, the package layer 240 has a sidewall 240C that
is not aligned to the edge 195. In some embodiments, the sidewall
240C is substantially parallel to the edge 195.
In some embodiments, the package layer 240 fills the space 230
between the integrated circuit dies 210 and the passivation layer
190. As a result, the package layer 240 continuously surrounds the
connectors 220. In some embodiments, the package layer 240 is in
direct contact with the connectors 220, the integrated circuit dies
210 and the passivation layer 190.
Many variations and/or modifications can be made to embodiments of
the disclosure. In some other embodiments, the space 230 is filled
with another package layer that is surrounded by the package layer
240. As a result, the package layer 240 is not in direct contact
with the connectors 220.
As shown in FIG. 2, the package layer 240 extends along the edge
195, in accordance with some embodiments. As a result, the package
layer 240 continuously surrounds the integrated circuit dies 210.
In some embodiments, the package layer 240 is spaced apart from the
edge 195. In some embodiments, the package layer 240 is retracted
inwardly from the edge 195. In some embodiments, the package layer
240 has a size or diameter that is less than that of the carrier
substrate 100. As a result, the package layer 240 partially exposes
the passivation layer 190.
In some embodiments, the package layer 240 includes a polymer
material or another suitable encapsulating material. In some
embodiments, the package layer 240 includes a molding compound. In
some embodiments, the package layer 240 has a coefficient of
thermal expansion (CTE) in a range from about 9 ppm/.degree. C. to
about 20 ppm/.degree. C. In some embodiments, the package layer 240
has fillers dispersed therein. The fillers may include insulating
fibers, insulating particles, other suitable elements, or a
combination thereof. In some embodiments, the content or
concentration of the fillers dispersed in the package layer 240 is
in a range from about 70 wt % to about 85 wt %. In some
embodiments, the size of the fillers dispersed in the package layer
240 is in a range from about 10 .mu.m to about 20 .mu.m. In some
embodiments, the package layer 240 is formed by an immersion
molding process, another applicable process, or a combination
thereof.
As shown in FIG. 1F, a package layer 250 is formed over the
passivation layer 190, in accordance with some embodiments. The
package layer 250 caps the package layer 240 and the integrated
circuit dies 210. In some embodiments, the package layer 250 covers
the sidewall 240C of the package layer 240. In some embodiments,
the package layer 250 extends over the non-active surface 210B of
the integrated circuit dies 210 to cover the top surface of the
package layer 240. As a result, the package layer 240 is embedded
in the package layer 250.
In some embodiments, the package layer 250 is in direct contact
with the package layer 240 and the passivation layer 190. In some
embodiments, the package layer 250 extends from the sidewall 240C
of the package layer 240 to the edge 195. In some embodiments, the
package layer 250 further extends to cover the edge 195. In some
embodiments, the package layer 250 has a sidewall 250C that is not
aligned to the sidewall 240C and the edge 195. In some embodiments,
the sidewall 250C is substantially parallel to the sidewall 240C
and/or the edge 195.
As shown in FIG. 2, the package layer 250 extends along the edge
195, in accordance with some embodiments. As a result, the package
layer 250 continuously surrounds the edge 195. In some embodiments,
the package layer 250 extends across the edge 195. In some
embodiments, the package layer 250 has a size or diameter that is
greater than that of the carrier substrate 100 and the package
layer 240.
In some embodiments, the package layer 250 includes a polymer
material or another suitable encapsulating material. In some
embodiments, the package layer 250 includes a molding compound. In
some embodiments, the package layers 240 and 250 include the same
material. However, embodiments of the disclosure are not limited
thereto. In some other embodiments, the package layers 240 and 250
include different materials. The package layer 250 may include
multiple sub-layers.
In some embodiments, the package layer 250 has a CTE in a range
from about 15 ppm/.degree. C. to about 35 ppm/.degree. C. The CTE
of the package layer 250 may be less than, substantially equal to
or greater than that of the package layer 240. The CTE of the
package layer 250 can be varied according to requirements.
In some embodiments, the package layer 250 has fillers dispersed
therein. The fillers may include insulating fibers, insulating
particles, other suitable elements, or a combination thereof. In
some embodiments, the content or concentration of the fillers
dispersed in the package layer 250 is in a range from about 65 wt %
to about 80 wt %. In some embodiments, the size of the fillers
dispersed in the package layer 250 is in a range from about 20
.mu.m to about 75 .mu.m. In some embodiments, the fillers dispersed
in the package layer 250 have a (maximum) size that is greater than
the fillers dispersed in the package layer 240.
In some embodiments, the package layer 250 is formed by a
compression molding process, an immersion molding process, another
applicable process, or a combination thereof. In some embodiments,
a liquid molding compound material is applied over the passivation
layer 190 and the package layer 240 to encapsulate and cap the
package layer 240 and the integrated circuit dies 210. In some
embodiments, a thermal process is then applied to harden the
molding compound material and to transform it into the package
layer 250. In some embodiments, the thermal process is performed at
a temperature in a range from about 200.degree. C. to about
230.degree. C. The operation time of the thermal process may be in
a range from about 1 hour to about 3 hours.
As shown in FIG. 1F, the carrier substrate 100 is removed from the
passivation layer 120, in accordance with some embodiments. As a
result, the conductive layer 140 in the openings 130 of the
passivation layer 120 is partially exposed. In some embodiments,
the carrier substrate 100 is detached from the passivation layer
120 by light irradiation on the adhesive layer 110.
In some embodiments, the carrier substrate 100 is detached from the
passivation layer 120 after the formation of the package layer 250.
As a result, the conductive layer 140 in the openings 130 is
protected by the carrier substrate 100 during the formation of the
package layer 250. However, embodiments of the disclosure are not
limited thereto. In some other embodiments, the carrier substrate
100 is detached from the passivation layer 120 before the formation
of the package layer 250.
As shown in FIG. 1G, the structure shown in FIG. 1F is reversed. As
a result, the integrated circuit dies 210 are supported by the
package layers 240 and 250 after the removal of the carrier
substrate 100. In some embodiments, there is no carrier substrate
attached to the package layers 240 and 250 during subsequent
processes.
As shown in FIG. 1G, the exposed portions of the conductive layer
140 are recessed in the openings 130, in accordance with some
embodiments. As a result, the conductive layer 150 in the openings
130 is partially exposed. There is a recessed depth D that is
measured from the surface 120A of the passivation layer 120 to the
recessed conductive layer 140. In some embodiments, the recessed
depth D is in a range from about 0.01 .mu.m to about 0.5 .mu.m.
In some embodiments, an etching process is used to recess the
exposed portions of the conductive layer 140. The etching process
is a dry etching process or a wet etching process. In some
embodiments, the etching process is performed until the conductive
layer 150 is exposed. In some embodiments, the conductive layer 150
is partially removed during the etching process.
In some cases, the exposed portions of the conductive layer 140 may
be oxidized during processing. The oxidized portions of the
conductive layer 140 are removed until the conductive layer 150 is
exposed. As a result, the resistance between the conductive layer
150 and the subsequently formed conductive feature is prevented
from being increased undesirably. Therefore, the electrical
performance and reliability of the package structure is
significantly enhanced.
As shown in FIG. 1H, connectors 260 are formed to cover the
openings 130, in accordance with some embodiments. As a result, the
connectors 260 fill the openings 130 to electrically connect to the
integrated circuit dies 210 through the conductive layer 150 in the
openings 130. In some embodiments, the connectors 260 and the
conductive layers 140 and 150 together fill the openings 130.
In some embodiments, the connectors 260 and the conductive layer
150 in the openings 130 gradually shrink along a direction from the
integrated circuit dies 210 towards the connectors 260. In some
embodiments, the connectors 260 and the conductive layer 150 in the
openings 130 gradually shrink along a direction from the non-active
surface 210B toward the active surface 210A of the integrated
circuit dies 210. As a result, the conductive layer 150 in the
openings 130 has a taper structure.
In some embodiments, each of the connectors 260 includes a
conductive layer 266, a conductive bump 262 and a solder layer 264.
The conductive bump 252 is between the conductive layer 266 and the
solder layer 264.
FIG. 3 shows is an enlarged cross-sectional view of a portion P of
the structure shown in FIG. 1H, in accordance with some
embodiments. As shown in FIG. 3, the conductive layer 266 extends
over the surface 120A of the passivation layer 120 and fills the
openings 130, in accordance with some embodiments. The sidewall
120C is covered by the conductive layer 266 and the conductive
layer 140. In some embodiments, a portion of the conductive layer
266 is sandwiched between the conductive layer 150 and the
conductive bump 262. In some embodiments, the conductive layer 266
is in direct contact with the conductive layers 140 and 150.
In some embodiments, there is an interface 260A between the
conductive layer 266 and the conductive layers 140 and 150. In some
embodiments, the angle .theta. between the sidewall 120C and the
interface 260A is greater than 0.degree. and is less than or
substantially equal to 90.degree.. In some embodiments, the surface
120A of the passivation layer 120 is closer to the interface 260A
than the surface 120B of the passivation layer 120.
In some embodiments, the conductive layer 266 is a seed layer. In
some embodiments, the conductive layer 266 includes Ti. However,
embodiments of the disclosure are not limited thereto. For example,
the conductive layer 266 may include Ti alloy, Cu, Cu alloy,
another suitable seed material, or a combination thereof. In some
embodiments, the conductive layer 266 is deposited using a PVD
process, a CVD process, another applicable process, or a
combination thereof.
Many variations and/or modifications can be made to embodiments of
the disclosure. In some other embodiments, the conductive layer 266
is an under bump metallurgy (UBM) layer. The UBM layer may include
a diffusion barrier layer and a seed layer. The seed layer is
between the diffusion barrier layer and the conductive bump 262.
The diffusion barrier layer may include tantalum nitride, titanium
nitride, tantalum, titanium, another suitable material, or a
combination thereof.
In some embodiments, the conductive bump 262 extends over the
surface 120A and fills the openings 130. In some other embodiments,
the conductive bump 262 does not fill the openings 130. The
conductive bump 262 may be a conductive pillar, another suitable
conductive feature, or a combination thereof. In some embodiments,
the conductive bump 262 includes copper, ENIG, ENEPIG, another
suitable material, or a combination thereof. In some embodiments,
the conductive bump 262 is deposited using an electroplating
process, a sputtering process, another applicable process, or a
combination thereof. Multiple deposition, coating, and/or etching
processes may be used to form the connectors 260 including the
conductive layer 266, the conductive bump 262 and the solder layer
264.
Many variations and/or modifications can be made to embodiments of
the disclosure. In some other embodiments, the connectors 260 do
not include conductive pillars. In some other embodiments, the
connectors 260 are solder bumps, solder balls, other suitable
connectors, or a combination thereof. In some embodiments, the
connectors 260 are controlled collapse chip connection (C4) bumps
and/or ball grid array (BGA) bumps.
As shown in FIG. 1I, the package layers 240 and 250 are partially
removed, in accordance with some embodiments. As a result, the
non-active surface 210B of the integrated circuit dies 210 is
exposed. It is advantageous for heat dissipation of the integrated
circuit dies 210. In some embodiments, the edge 195 stays covered
by the package layer 250 during the partial removal of the package
layers 240 and 250.
In some embodiments, a planarization process is used to partially
remove and thin the package layers 240 and 250. The planarization
process includes a grinding process, a chemical mechanical
polishing (CMP) process, an etching process, another applicable
process, or a combination thereof.
Afterwards, a singulation process is performed to form multiple
package structures. Each of the package structures includes one or
more integrated circuit dies 210 embedded in the package layer 240,
as shown in FIG. 1I. In some embodiments, the singulation process
includes a dicing process to cut the package layer 240 and the
passivation layer 120 along scribe lines by a saw blade or laser
beam. The scribe lines extend around the integrated circuit dies
210 and intersect the edge 195. In some embodiments, each of the
package structures is separated from the package layer 250 after
the singulation process. As a result, the package layer 250 is
removed from each of the package structures, as shown in FIG.
1I.
Although FIG. 1I shows that the non-active surface 210B of the
integrated circuit dies 210 is exposed, embodiments of the
disclosure are not limited thereto. In some other embodiments, the
non-active surface 210B of the integrated circuit dies 210 stays
covered by the package layers 240 and 250 during the singulation
process. As a result, each of the package structures includes one
or more integrated circuit dies 210 covered by the package layers
240 and 250.
Many variations and/or modifications can be made to embodiments of
the disclosure. FIG. 4 is a cross-sectional view of a package
structure, in accordance with some embodiments. In some
embodiments, the materials and/or formation methods of the package
structure shown in FIG. 4 are similar to those of the package
structure shown in FIG. 1I.
As shown in FIG. 4, a package layer 270 fills the space 230 between
the active surface 210A of the integrated circuit dies 210 and the
passivation layer 190, in accordance with some embodiments. As a
result, the connectors 220 are surrounded by the package layer 270.
In some embodiments, the package layer 270 does not extend over the
non-active surface 210B of the integrated circuit dies 210. As a
result, the integrated circuit dies 210 are partially embedded in
the package layer 270. In some embodiments, the package layer 270
has a sidewall 270C that is inclined to the sidewall 240C of the
package layer 240.
In some embodiments, the package layer 270 includes an underfill
material or another suitable encapsulating material. In some
embodiments, the package layer 270 includes a material that is
different from that of the package layer 240 and/or the package
layer 250.
In some embodiments, the package layer 270 has fillers dispersed
therein. The fillers may include insulating fibers, insulating
particles, other suitable elements, or a combination thereof. In
some embodiments, the content or concentration of the fillers
dispersed in the package layer 270 is in a range from about 60 wt %
to about 85 wt %. In some embodiments, the size of the fillers
dispersed in the package layer 270 is in a range from about 5 .mu.m
to about 20 .mu.m. In some embodiments, the fillers dispersed in
the package layer 240 and/or the package layer 250 have a (maximum)
size that is greater than the fillers dispersed in the package
layer 270.
In some embodiments, the package layer 270 is formed by a
dispensing process, another applicable process, or a combination
thereof. In some embodiments, a liquid underfill material is
dispensed by capillary action and cured to form the package layer
270. In some embodiments, the package layer 270 is formed before
the formation of the package layers 240 and 250.
Although FIG. 4 shows that the package structure has a non-active
surface 210B of the integrated circuit dies 210 that is covered by
the package layers 240 and 250, embodiments of the disclosure are
not limited thereto. In some other embodiments, the package layers
240 and 250 are removed until the non-active surface 210B is
exposed. As a result, the package structure does not include the
package layer 250.
Many variations and/or modifications can be made to embodiments of
the disclosure. FIGS. 5A and 5B are cross-sectional views of
various stages of a process for forming a package structure, in
accordance with some embodiments.
As shown in FIG. 5A, connectors 280 are formed over the passivation
layer 190 and fill the openings 200 to electrically connect to the
conductive layer 180, in accordance with some embodiments. In some
embodiments, each of the connectors 280 includes a conductive bump
282 and a solder layer 284. The conductive bump 282 is between the
conductive layer 180 and the solder layer 284. The conductive bump
282 may be a conductive pillar, another suitable conductive
feature, or a combination thereof. In some embodiments, the
conductive bump 282 includes copper, ENIG, ENEPIG, another suitable
material, or a combination thereof.
Embodiments of the disclosure are not limited thereto. In some
other embodiments, the connectors 280 include the conductive bump
282 without the solder layer 284. In some other embodiments, the
connectors 280 do not include conductive pillars. In some other
embodiments, the connectors 280 are solder bumps, solder balls,
other suitable connectors, or a combination thereof.
Afterwards, multiple integrated circuit dies 210 are bonded to the
conductive layer 180 through the connectors 220 and 280, in
accordance with some embodiments. The connectors 220 are coupled to
the integrated circuit dies 210 before bonding the integrated
circuit dies 210. In some embodiments, a reflow process is
performed to bond the solder layer 284 of the connectors 280 and
the solder layer 224 of the connectors 220 together.
Subsequently, the steps described in FIGS. 1E-1H are performed to
form the structure shown in FIG. 5B. In some embodiments, the
package layer 240 fills the space 230 between the integrated
circuit dies 210 and the passivation layer 190. As a result, the
package layer 240 continuously surrounds the connectors 220 and
280. In some embodiments, the package layer 240 is in direct
contact with the connectors 220 and 280. Afterwards, a singulation
process is performed over the structure shown in FIG. 5B to form
multiple package structures.
Embodiments of the disclosure provide a method for forming a
package structure. The method includes forming a redistribution
structure over a carrier wafer, and subsequently bonding an
integrated circuit die to the redistribution structure through
connectors. The method also includes forming a first package layer
surrounding the integrated circuit die and the connectors. The
first package layer is retracted inwardly from the wafer edge. The
method further includes forming a second package layer that covers
the sidewall of the first package layer and extends to the wafer
edge. Due to the second package layer, it is advantageous for
manufacturing equipment to handle or clamp the wafer structure with
the first and second package layers. As a result, subsequent
processes are successively performed over the wafer structure.
In accordance with some embodiments, the material of the second
package layer is selected to control the degree of warpage of the
wafer structure. For example, the material of the second package
layer may have a high CTE to increase the warpage degree and result
in positive warping. Alternatively, the material of the second
package layer may have a low CTE to reduce the warpage degree and
result in negative warping. As a result, the warpage degree of the
wafer structure is compensated for by the second package layer.
Accordingly, the package structure is prevented from cracking and
has improved planarization. Therefore, the reliability of the
package structure is significantly enhanced.
Furthermore, after the carrier wafer is removed, the second package
layer provides support during the subsequent processes. No
additional carrier wafer is attached to the first package layer. In
accordance with some embodiments, the material of choice for the
second package layer is substantially not critical. The second
package layer may include a molding compound having fillers with a
large size, rather than fine fillers. Accordingly, the method for
forming the package structure is simple and the fabrication cost of
the package structure is greatly reduced.
In addition, since the redistribution structure is formed before
bonding the integrated circuit die (i.e., die last process), the
integrated circuit die is prevented from being damaged during
high-temperature processes for forming the redistribution
structure. As a result, thermal loading of the integrated circuit
die is reduced. Accordingly, reliability of the package structure
is significantly enhanced.
In accordance with some embodiments, a package structure is
provided. The package structure includes a package layer. The
package structure also includes an integrated circuit die and a
first connector embedded in the package layer. The package
structure further includes a redistribution layer over the package
layer. The integrated circuit die is electrically connected to the
redistribution layer through the first connector. In addition, the
package structure includes a passivation layer over the
redistribution layer. The package structure also includes a second
connector over the passivation layer. A first portion of the
redistribution layer and a second portion of the second connector
extend into the passivation layer. The second portion of the second
connector has a tapered profile along a direction from the
integrated circuit die towards the first connector.
In accordance with some embodiments, a package structure is
provided. The package structure includes a package layer. The
package structure also includes an integrated circuit die embedded
in the package layer. The integrated circuit die has an active
surface and a non-active surface. The package structure further
includes a bump embedded in the package layer. The bump is coupled
to the active surface. In addition, the package structure includes
a redistribution layer over the package layer. The integrated
circuit die is electrically connected to the redistribution layer
through the bump. The package structure also includes a passivation
layer over the redistribution layer. The package structure further
includes a connector over the passivation layer. A first portion of
the redistribution layer and a second portion of the connector
extend into the passivation layer. The first portion gradually
shrinks along a direction from the non-active surface toward the
active surface.
In accordance with some embodiments, a package structure is
provided. The package structure includes a package layer. The
package structure also includes an integrated circuit die and a
bump embedded in the package layer. The package structure further
includes a redistribution layer over the package layer. The
integrated circuit die is electrically connected to the
redistribution layer through the bump. In addition, the package
structure includes a passivation layer over the redistribution
layer. A first portion of the redistribution layer extends into the
passivation layer. The passivation layer comprises a sidewall
adjoining the first portion of the redistribution layer. The
package structure also includes a connector over the passivation
layer. A second portion of the connector extends into the
passivation layer to electrically connect to the redistribution
layer. There is an acute angle between the sidewall of the
passivation layer and a first surface of the passivation layer
facing the connector.
The foregoing outlines features of several embodiments so that
those skilled in the art may better understand the aspects of the
present disclosure. Those skilled in the art should appreciate that
they may readily use the present disclosure as a basis for
designing or modifying other processes and structures for carrying
out the same purposes and/or achieving the same advantages of the
embodiments introduced herein. Those skilled in the art should also
realize that such equivalent constructions do not depart from the
spirit and scope of the present disclosure, and that they may make
various changes, substitutions, and alterations herein without
departing from the spirit and scope of the present disclosure.
* * * * *